1: Crossfader... this can be done.
2: List View ... Album art and artist photo views is kind of annoying when you have a huge collection.
3: Multi-Room Controls should be better. I should be able to control volumes for different audio chrome cast like you can from the chrome cast app.
4: Multi-device control for multi room setups. If there are separate rooms there probably are separate devices. it would be nice to continue control of a playlist that you started in one room and are then listening to in another.